添加CaAl4O7-MgAl2O4对低碳镁碳砖抗热震性的影响

摘要

The basic formulation of low carbon MgO-C brick is 93 mass% (similarly hereinafter) magnesite, 3% aluminum powder,4% graphite,extra adding 4% phenolic resin. Effects of CaAI4O7-MgAI2O4 composite additions (2%, 4%, 6% and 8%, respectively) on thermal shock resistance of low carbon MgO-C bricks were researched using CaAI4O7-MgAI2O4 to replace equivalent magnesite. The results show that, with CaAI4O7-MgAI2O4 addition increasing,the thermal expansion coefficient,the modulus of elasticity (E) and the hot modulus of rupture (Re) of the low-carbon MgO-C brick decrease, but the index of Rg/E standing for thermal shock resistance increases. Therefore,CaAI4O7-MgAI2O4 is beneficial to improve the thermal shock resistance of low carbon MgO-C brick, but excessive is harmful, and the appropriate addition is 6%.%在以93％(w)镁砂、3％(w)铝粉、4％(w)石墨、外加4％(w)酚醛树脂为基础配方的低碳镁碳砖组成中,采用CaAl4O7-MgAl2O4复合材料为添加剂等量取代镁砂,研究其加入量(其质量分数分别为2％、4％、6％、8％)对低碳镁碳砖抗热震性的影响.结果表明:随着添加剂加入量的增大,低碳镁碳砖的热膨胀系数、弹性模量(E)及高温抗折强度(Re)基本上均呈下降趋势,而抗热震性Re/E指数增大.因此,添加CaAl4O7-MgAl2O4有利于提高低碳镁碳砖抗热震性;但添加过量时,对抗热震性不利,以添加6％(w)为宜.